hwmon: (adm1031) Fix writes to limit registers

commit 145e74a4 upstream.

Upper limit for write operations to temperature limit registers
was clamped to a fractional value. However, limit registers do
not support fractional values. As a result, upper limits of 127.5
degrees C or higher resulted in a rounded limit of 128 degrees C.
Since limit registers are signed, this was stored as -128 degrees C.
Clamp limits to (-55, +127) degrees C to solve the problem.

Value on writes to auto_temp[12]_min and auto_temp[12]_max were not
clamped at all, but masked. As a result, out-of-range writes resulted
in a more or less arbitrary limit. Clamp those attributes to (0, 127)
degrees C for more predictable results.

Cc: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[bwh: Backported to 3.2:
 - Adjust context
 - Driver was using SENSORS_LIMIT(), which we can replace with clamp_val()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/hwmon/adm1031.c

@@ -352,6 +352,7 @@ set_auto_temp_min(struct device *dev, struct device_attribute *attr,
 	int nr = to_sensor_dev_attr(attr)->index;
 	int val = simple_strtol(buf, NULL, 10);
 
+	val = clamp_val(val, 0, 127000);
 	mutex_lock(&data->update_lock);
 	data->auto_temp[nr] = AUTO_TEMP_MIN_TO_REG(val, data->auto_temp[nr]);
 	adm1031_write_value(client, ADM1031_REG_AUTO_TEMP(nr),
@@ -376,6 +377,7 @@ set_auto_temp_max(struct device *dev, struct device_attribute *attr,
 	int nr = to_sensor_dev_attr(attr)->index;
 	int val = simple_strtol(buf, NULL, 10);
 
+	val = clamp_val(val, 0, 127000);
 	mutex_lock(&data->update_lock);
 	data->temp_max[nr] = AUTO_TEMP_MAX_TO_REG(val, data->auto_temp[nr], data->pwm[nr]);
 	adm1031_write_value(client, ADM1031_REG_AUTO_TEMP(nr),
@@ -651,7 +653,7 @@ static ssize_t set_temp_min(struct device *dev, struct device_attribute *attr,
 	int val;
 
 	val = simple_strtol(buf, NULL, 10);
-	val = SENSORS_LIMIT(val, -55000, nr == 0 ? 127750 : 127875);
+	val = clamp_val(val, -55000, 127000);
 	mutex_lock(&data->update_lock);
 	data->temp_min[nr] = TEMP_TO_REG(val);
 	adm1031_write_value(client, ADM1031_REG_TEMP_MIN(nr),
@@ -668,7 +670,7 @@ static ssize_t set_temp_max(struct device *dev, struct device_attribute *attr,
 	int val;
 
 	val = simple_strtol(buf, NULL, 10);
-	val = SENSORS_LIMIT(val, -55000, nr == 0 ? 127750 : 127875);
+	val = clamp_val(val, -55000, 127000);
 	mutex_lock(&data->update_lock);
 	data->temp_max[nr] = TEMP_TO_REG(val);
 	adm1031_write_value(client, ADM1031_REG_TEMP_MAX(nr),
@@ -685,7 +687,7 @@ static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr,
 	int val;
 
 	val = simple_strtol(buf, NULL, 10);
-	val = SENSORS_LIMIT(val, -55000, nr == 0 ? 127750 : 127875);
+	val = clamp_val(val, -55000, 127000);
 	mutex_lock(&data->update_lock);
 	data->temp_crit[nr] = TEMP_TO_REG(val);
 	adm1031_write_value(client, ADM1031_REG_TEMP_CRIT(nr),